Allāhumma rabba hādhihi 'd-da'wati 't-tāmmahwaṣ-ṣalāti 'l-qā'imah,'āti Muhammadani 'l-wasīlata walfaḍīlata. wab 'ath-hu maqāma 'm-mahmūdani 'l-ladhī wa`adtahu, ['innaka lā tukhliful-mī'ād]
O Allah, Lord of this perfect call and established prayer. Grant Muhammad the intercession and favor, and raise him to the honored station You have promised him, [verily You do not neglect promises].
Reference:
Al-Bukhari 1/152, and the addition between brackets is from Al-Bayhaqi 1/410 with a good (Hasan) chain of narration. See 'Abdul-Azlz bin Baz's Tuhfatul-'Akhyar, pg. 38.
Hisnul Muslim 25