What are the conditions for the permissibility of polygyny?

Polygyny is desirable if financial and physical ability are present, along with justice among wives, due to the benefits it offers, such as protecting women, expanding connections, and increasing offspring, which the Prophet ﷺ encouraged with his saying: "Marry the affectionate, the fertile." However, marrying more than one woman for boasting and defiance is a forbidden extravagance. Allah Almighty says: (And do not be extravagant; indeed, He does not like the extravagant.)