“Just a little.” Notice this sentence is in quotation marks. This is either the son talking back to the father, or the father mimicing the words of the son as to why he won’t get up. The son wants, “just a little more sleep.”
“folding of the arms.” The Hebrew uses the word “hands” but culturally the “hand” included the wrist and forearm. This is why Jesus was nailed to a cross through his “hands” but the part of Jesus’ body the nails went through was his wrists. The person lying on his bed ignored the father’s advice to get up, and folded his arms, which was likely comfortable, but also likely had overtones of rejection—that he was refusing his father’s request.