Narrated Anas:

"The Prophet ﷺ passed by old man walking (while supported) between his two sons, so he said: 'What is the matter with this one?' They said: "O Messenger of Allah! He vowed to walk.' He said: 'Verily Allah [the Mighty and Sublime] is in no need of this person punishing himself.'" He said: "So he ordered him to ride."

حَدَّثَنَا أَبُو مُوسَى، مُحَمَّدُ بْنُ الْمُثَنَّى حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، حَدَّثَنَا حُمَيْدٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ مَرَّ النَّبِيُّ ﷺ بِشَيْخٍ كَبِيرٍ يَتَهَادَى بَيْنَ ابْنَيْهِ فَقَالَ " مَا بَالُ هَذَا " . قَالُوا يَا رَسُولَ اللَّهِ نَذَرَ أَنْ يَمْشِيَ . قَالَ " إِنَّ اللَّهَ عَزَّ وَجَلَّ لَغَنِيٌّ عَنْ تَعْذِيبِ هَذَا نَفْسَهُ " . قَالَ فَأَمَرَهُ أَنْ يَرْكَبَ .