I say, and with God's success: If they are young, the obligation is on the father, not on them; because they are the reason for the obligation on the father, and his failure to provide will return to him with sin, not to them. If they are adults, the obligation is on them, not on the father if they are wealthy. If they are not wealthy, then the obligation is not required from him or them due to their poverty. The wife, if she is wealthy, is obligated, and if she is poor, then it is not required. And God knows best.