Muhammad bin Ya‘qub narrated from Ali bin Ibrahim, from Muhammad bin ‘Isa, from Yunus, from Zur‘ah, from Sama‘ah, who said: Abu Abdullah عليه السلام said: "If you enter the lavatory and relieve yourself but do not pour water (for purification), then you perform ablution and forget to perform istinja (purification) but remember after you have prayed, then you must repeat the prayer. But if you poured water (for ablution) and then forgot to wash your private part until after you prayed, then you must repeat both the ablution and the prayer and wash your private part, because urine is like excrement."