Ibn Abbas narrated: "The Prophet (S) would pray thirteen Rak'ah at night".
The number of rak’ahs that were prayed by the Prophet SAW can also be seen as an indication of how important it is for us to spend time in prayer with Allah SWT. It shows us that if we want our prayers to be accepted then we must put in effort into them; not just physically but spiritually too. We must make sure that our hearts are open and sincere when praying so that Allah SWT will accept our supplications with mercy and grace.