'Conception' in the Bible

Onan knew that the child (heir) would not be his [but his dead brother’s]; so whenever he lay with his brother’s widow, he spilled his seed on the ground [to prevent conception], so that he would not give a child to his brother.

A little leaven [a slight inclination to error, or a few false teachers] leavens the whole batch [it perverts the concept of faith and misleads the church].

The Lord does not delay [as though He were unable to act] and is not slow about His promise, as some count slowness, but is [extraordinarily] patient toward you, not wishing for any to perish but for all to come to repentance.