(42) بَابُ قَوْلِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الدِّينُ النَّصِيحَةُ لِلَّهِ وَلِرَسُولِهِ وَلأَئِمَّةِ الْمُسْلِمِينَ وَعَامَّتِهِمْ»
Narrated 'Umar bin Al-Khattab:
Allah's Messenger (ﷺ) said, "The reward of deeds depends upon the intention and every person will get the reward according to what he has intended. So whoever emigrated for Allah and His Apostle, then his emigration was for Allah and His Apostle. And whoever emigrated for worldly benefits or for a woman to marry, his emigration was for what he emigrated for."
Reference: Sahih al-Bukhari 54
In-book reference: Book 2, Hadith 47
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 2, Hadith 52