For Have nothing to do see 1 Tim 4.7. Stupid and senseless are synonyms, with the former describing something that is without understanding, hence “nonsensical,” and the latter describing something that has not benefitted from proper education or formal training, hence “ignorant,” “foolish,” and even “ridiculous,” “pointless,” or “without any merit at all.” For controversies see 1 Tim 6.4.
You know is a participle (literally “knowing”) and implies that Timothy has prior knowledge of what is mentioned, which in this case is what results when people are involved in the propagation of false teachings.
Breed translates a verb whose ordinary meaning is “to beget” or “to give birth,” but in the present context it has the meaning of “to cause to happen,” hence “to produce.”
Quarrels translates the plural of a word that refers to a conflict, whether of a physical or a nonphysical nature. Another way to translate this final sentence is “I am sure that you know that such arguments only lead to fights.”
Quoted with permission from Arichea, Daniel C. and Hatton, Howard A. A Handbook on Paul’s Second Letter to Timothy. (UBS Handbook Series). New York: UBS, 1995. For this and other handbooks for translators see here .
