Manava Dharmashastra 11.47

11.47

prāyaścittīyatāṃ prāpya daivāt pūrvakṛtena vā
na saṃsargaṃ vrajet sadbhiḥ prāyaścitte 'kṛte dvijaḥ //

A twice-born man, having become liable to perform a penance, be it by (the decree of) fate or by (an act) committed in a former life, must not, before the penance has been performed, have intercourse with virtuous men.