The All-Patient, The Restrained, The Forbearing.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is As-Sabur (in Arabic: ٱلْصَّبُورُ), The One who is most patient and enduring. He does not act in a hastily manner but rather waits until the proper time. He does not punish the disobedient and unbelievers, He allows time for them to repent or an opportunity to take the right path.
From the root sad-ba-ra (ص ب ر), which has the following classical Arabic connotations: to be patient, to be enduring, to endure trial or affliction with good manner, to be contented in trial or affliction without show of complaint, to make no distinction between comfort and affliction, to bear calmly, to persevere cheerfully, to be steadfast, constant, to restrain, confine, withhold from something.
As we've mentioned in previous names, different scholars have different criteria for what qualifies as a name of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ. Of the 99 names, 81 are explicitly mentioned in the Qur'an. Therefore, there is not one agreed-upon list for the remaining 18 names. As-Sabur is one of those names which is not included by certain scholars. This list includes Ibn al-Wazir, Ibn Hazm, and Ibn al-Uthaymeen. However, others, such as Ibn Arabi, Imam al-Bayhaqi, and Imam al-Ghazali, have included this name in their lists.
The name of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ as-Sabur, the patient. As we come to know from these attributes, Allah's blessings are immense. We are forever indebted to Him and we could never reciprocate or do enough to equalize the blessings He's given us. The gift of life, our health, faith, and it's sustenance in every moment is because of His will. In return, Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ commands from us very little and even in that we sometimes fall short. For example, even when we offer our Salah it can be deficient. Our bodies go through the motion, our tongues say the words, but our minds remain preoccupied with worldly distractions. We're thinking of things we can't wait to do after our prayer is over instead of being present in our salah. At other times we transgress the boundaries of acceptable behavior. We defy His command with things He has forbidden. In every situation He has complete right to exercise His power and give an equal punishment but He abstains. He withholds His right to convict and keeps the doors of repentance and forgiveness open. That is how merciful Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is. Even when there is reason to punish, He does not punish.
Imam al-Ghazali writes about this very nature of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ to delay. This restraint is not like a lazy person who procrastinates or a rash person who hastens to retaliate. Rather, as-Sabur is the one who disposes "each thing in its proper time, in the way in which it needs to be and according to what it requires." Everything is perfectly handled by Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ according to His definite plan.
Narrated Abu Musa: The Prophet ﷺ said: None is more patient than Allah against the harmful saying. He hears from the people they ascribe children to Him, yet He gives them health and (supplies them with) provision." 
In this hadith it describes Allah's attribute of being patient but does not refer to Him as the name As-Sabur, 'The Patient'. Similarily in the Qur'an we'll see verses describing His nature of showing respite.
Wa law yu’aakhizul laahun naasa bima kasaboo maa taraka ‘alaa zahrihaa min daaabbatinw wa laakiny yu’akhkhiruhum ilaaa ajalim musamman fa izaa jaaa’a ajaluhum fa innal laaha kaana bi’ibaadihee Baseeraa (section 5)
"And if Allah were to impose blame on the people for what they have earned, He would not leave upon the earth any creature. But He defers them for a specified term. And when their time comes, then indeed Allah has ever been, of His servants, Seeing." — (Qur'an 35:45)
But more commonly, you'll find Quranic passages and Hadith literature referencing how Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ loves and encourages us to be patient (i.e., showing sabr patience.) This includes patience in one's faith, patience/restraint in dealing with those who may try to harm you, and abstaining from foul language. It also extends to patience when dealing with some tragedy that has befallen you. So here, we'll shift focus to provide examples supporting these domains of patience. The Prophet said, "What wealth I have, I will not hoard from you. Whoever has forbearance, Allah will help him. Whoever tries to be independent, Allah will enrich him. Whoever tries to be patient, Allah will give him patience, and no one is given a better or vaster gift than patience." 
Wasbir wa maa sabruka illaa billaah; wa laa tahzan ‘alaihim wa laa taku fee daiqim mimmaa yamkuroon
"And be patient, [O Muhammad], and your patience is not but through Allah. And do not grieve over them and do not be in distress over what they conspire." — (Qur'an 16:27)
Yaaa ayyuhal laazeena aamanus ta’eenoo bissabri was Salaah; innal laaha ma’as-saabireen
"O you who have believed, seek help through patience and prayer. Indeed, Allah is with the patient." — (Qur'an 2:153)
Yaaa aiyuhal lazeena aamanus biroo wa saabiroo wa raabitoo wattaqul laaha la’allakum tuflihoon (section 20)
"O you who have believed, persevere and endure and remain stationed and fear Allah that you may be successful." — (Qur'an 3:200)
Narrated Anas: The Prophet ﷺ said, "The real patience is at the first stroke of a calamity." 
Fasbir sabran jameelaa
"So be patient with gracious patience." — (Qur'an 70:5)
It was narrated from Ibn ‘Umar that the Messenger of Allah ﷺ said: "The believer who mixes with people and bears their annoyance with patience will have a greater reward than the believer who does not mix with people and does not put up with their annoyance." 
The believer benefits from knowing that Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is both al-Haleem (The Clement) and As-Sabur (The Patient). We see Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ in the best light as a Lord who shows ultimate grace and patience for all of humanity. We see His treatment and gentleness as being caring, giving us a chance for redemption. A chance to turn back to Him if we've erred in any way. We should rejoice in knowing our creator is forbearing and does not hasten to punish even though it would be most just and deserving if He should.