What do you mean when the new son-in-law comes to the door and the mother-in-law sends insoles?

In China culture, parents of husband and wife often use small details to convey messages of missing, caring and blessing. Insole is often regarded as the mascot of marriage and family relations, and it also symbolizes the love and tacit understanding between newlyweds. Therefore, when a mother-in-law sends insoles to a new son-in-law, it usually means her welcome to the new son-in-law and her blessing to the newlyweds' happiness. This way shows the mother-in-law's hospitality, care and warmth, and hopes that the new son-in-law can respect, take care of and protect his wife.