Psalm 40:12

For innumerable evils have compassed me about
Like floods of water all around him; see ( Psalms 18:4 Psalms 18:5 ) ( Jonah 2:5 ) ; these are the evils of punishment inflicted on him, as the surety and Saviour of his people; such as the sorrows and griefs he bore all his days; the cruel mockings and scourges he endured; his being buffeted and spit upon; his head crowned with thorns, and his hands and feet pierced with nails; insulted by men and devils; crucified between two thieves, and so died the shameful and painful death of the cross;

mine iniquities have taken hold upon me;
not any committed by him; he was conceived, born, and lived without sin, knew none, nor did he any; but the sins of his people, which were imputed to him, laid upon him, and which he voluntarily took and bore; and which he reckoned as his own and was responsible for them; these, when he hung upon the cross, came upon him from all quarters, and he bore them in his own body upon the tree;

so that I am not able to look up;
or "cannot see" ^F16; either the end of these iniquities, they being so numerous, as is after related; or he could not bear to look upon them, they were so filthy and nauseous, and he so pure and holy; or he could not behold his Father's countenance, which these sins that were upon him separated him from, and caused to be hid from him; or, like one pressed down with the guilt of sin, as the poor publican was, could not so much as lift up his eyes to heaven, ( Luke 18:13 ) ;

they are more than the hairs of mine head;
as they must needs be, since they were the iniquities of all the elect of God, of the whole general assembly ad church of the firstborn, written in heaven, ( Isaiah 53:6 ) ;

therefore my heart faileth me;
as man; see ( Psalms 22:14 ) ; though being supported by his divine nature, and by his divine Father and eternal Spirit, he failed not, nor was he discouraged, ( Isaiah 42:4 ) ; this is said to show the truth of the human nature, the greatness of men's sins, the strictness of divine justice, and what strength was necessary to accomplish man's salvation.