Hadithcore
Sahih Muslim, 715 q
sahih

Jabir b. 'Abdullah (Allah be pleased with them) reported:

We were with Allah's Messenger (ﷺ) in a journey and my camel meant for carrying water lagged behind. The rest of the hadith is the same and it is mentioned also: Allah's Messenger (ﷺ) pricked it and then said to me: Ride in the name of Allah. He constantly made addition (in prayers for me) and went on saying. May Allah forgive you!

حَدَّثَنَا أَبُو كَامِلٍ الْجَحْدَرِيُّ، حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا الْجُرَيْرِيُّ، عَنْ أَبِي، نَضْرَةَ عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، قَالَ كُنَّا مَعَ النَّبِيِّ صلى الله عليه وسلم فِي سَفَرٍ فَتَخَلَّفَ نَاضِحِي ‏.‏ وَسَاقَ الْحَدِيثَ وَقَالَ فِيهِ فَنَخَسَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ قَالَ لِي ‏"‏ ارْكَبْ بِاسْمِ اللَّهِ ‏"‏ ‏.‏ وَزَادَ أَيْضًا قَالَ فَمَا زَالَ يَزِيدُنِي وَيَقُولُ ‏"‏ وَاللَّهُ يَغْفِرُ لَكَ ‏"‏ ‏.‏

References2 variants
In-Book Reference
Book 22, Hadith 141
USC-MSA web (English) reference
Book 10, Hadith 3890 (deprecated numbering scheme)