What is the explanation of the hadith in which my father asked the Prophet (peace be upon him): "How much of my prayers should I dedicate to you?" and he replied: "Then Allah will suffice you for your worries and forgive your sins"?

The Hadith inquired about by the questioner is authentic. Its meaning is that the Companion dedicated all his supplications to sending blessings upon the Prophet, peace and blessings be upon him. The Prophet then informed him that this would suffice him for his worries in this world and the Hereafter.