John Wesley on 2 Samuel 19:24

The son - That is, the grandson, 2Sam 6:3,6. His feet - By washing his feet, which was usual in those hot climates, and very refreshing; and therefore now neglected, as becoming a mourner. Beard - But suffered it to grow very long, and disorderly, as was usual with persons in a forlorn, or mournful state. Clothes - His linen cloathes. This and the former were signs, that he was a true and obstinate mourner, and evidences of the falsehood of Ziba's relation concerning him, chap.16:3.