Atharvaveda 7.90.3

7.90.3

yáthā śépo apā́yātai strīṣú cā́sad ánāvayāḥ |
avasthásya knadī́vataḥ śāṅkurásya nitodínaḥ |
yád ā́tatam áva tát tanu yád úttataṃ ní tát tanu ||3||

That the member may go off, and may be impotent (? ánāvayas) toward women, of the depending, inciting (?), peg-like, in-thrusting one, what is stretched, that do thou unstretch; what is stretched up, that do thou stretch down.