At the time of emission of sperm
Posted by amad on October 21 2008 03:13:01
When the sperm comes out, recite the following dua in the heart:
اللَّهُمَّ لَا تَجْعَلْ لِلشَّيْطَانِ فِيمَا رَزَقْتَنِي نَصِيبَاً
"O Allah, let Satan not be part of the children You grant us".