+ Positive Mitzvah
To marry a wife and have children
‘’God said be fruitful and multiply “Bereishis 1;28
God said be fruitful and multiply in order to perpetuate humanity.
When a man is 18 he is obligated to procreate and multiply.
If he is above 20 and not married, he disobeys this positive commandment.
If occupied with Torah and fearful that earning a livelihood will interfere, he can delay but not beyond the age of 25.
This applies in all places at all times.