20. observest—Thou dost not keep them. The "many things" are the many proofs which all along from the first God had given Israel of His goodness and His power (De 4:32-38; 29:2-4; Ps 78:1-72; 105:1-45).
he—transition from the second to the third person. "Opening … ears," that is, though he (Israel) hath his ears open (see on Isa 6:10). This language, too (see on Isa 42:19), applies to Messiah as Jehovah's servant (Isa 50:5; Ps 40:6).