What is incumbent upon me regarding my parents after traveling for work, knowing that they are in good health and did not object to my travel, and I am married with four children?

It is permissible for you to travel for trade as long as your parents do not need you and you do not fear for their loss, as jurists have stipulated the permissibility of a child traveling for trade or other purposes without the parents' permission if the journey is safe. It is even more permissible if they give permission. You should be dutiful and kind to them by visiting them, checking on them, contacting them, and offering them assistance, especially when needed. You must balance the rights of your parents with the rights of your wife and children.