Jami` at-Tirmidhi 2876

Narrated Abu Hurairah:"The Messenger of Allah (ﷺ) sent an expedition force [comprised] of many, and he asked each what he could recite, so each one of them mentioned what he could recite - meaning what he had memorized of the Qur'an. He came to one of the youngest men among them and said: 'What have you memorized O so-and-so?' He said: 'I memorized this and that and Surat Al-Baqarah.' He said: 'You memorized Surat Al-Baqarah?' He said: "Yes.' He said: "Then go, for you are their commander.' A man among their chief said: 'By Allah [O Messenger of Allah]! Nothing prevented me from learning Surat Al-Baqarah except fearing that I would not be able to stand with (in voluntary night prayer).' The Messenger of Allah (ﷺ) said: 'Learn the Qur'an to recite it, for indeed the parable of the Qur'an for the one who recites it and stands with it (in prayer) is that of a bag full of musk whose scent fills the air all around. And the parable of the one who learns it then sleeps while it is in his memory is that of a bag containing musk that is tied shut