Clement of Alexandria
If a man who has just constructed a home has not yet had the opportunity to dwell in it, or if he has cultivated a new vineyard but has not yet gathered its yield, or if he has pledged to marry a woman but has not yet taken her as his wife, the principles of human affection dictate that such individuals should be exempt from military duty. This is justified militarily, as being preoccupied with personal desires can hinder one's ability to fight with diligence (for those who enter into perilous situations must be free from distraction). Additionally, it is morally sound, as the Law recognizes the uncertainty of warfare and deemed it unfair for one to toil for the fruits of his labor while another reaps the benefits without having exerted effort.