Mishkat al-Masabih, hadith 240

وَعَنْ عَائِشَةَ أَنَّهَا قَالَتْ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «إِنَّ اللَّهَ عَزَّ وَجَلَّ أَوْحَى إِلَيَّ أَنَّهُ مَنْ سَلَكَ مَسْلَكًا فِي طَلَبِ الْعِلْمِ سَهَّلْتُ لَهُ طَرِيقَ الْجَنَّةِ وَمَنْ سَلَبْتُ كَرِيمَتَيْهِ أَثَبْتُهُ عَلَيْهِمَا الْجَنَّةَ. وَفَضْلٌ فِي عِلْمٍ خَيْرٌ مِنْ فَضْلٍ فِي عِبَادَةٍ وَمِلَاكُ الدِّينِ الْوَرَعُ» . رَوَاهُ الْبَيْهَقِيُّ فِي شعب الْإِيمَان

‘Aisha said she heard God’s messenger say that God revealed to him, “ If anyone follows a path in search of knowledge, I shall make easy for him the road to paradise; and if I deprive anyone of his eyes, I shall guarantee paradise to him in return for them. Superiority in knowledge is better than superiority in worship, and the basis of the religion is abstinence.” Baihaqi transmitted it in Shu'ab al-iman.