These are comforting words.
Psa 121:1 A Song of degrees. I will lift up mine eyes unto the hills, from whence cometh my help.
His presence was in the temple high in Jerusalem.
Psa 121:2 My help cometh from the LORD, which made heaven and earth.
Psa 121:3 He will not suffer thy foot to be moved: he that keepeth thee will not slumber.
Psa 121:4 Behold, he that keepeth Israel shall neither slumber nor sleep.
He knows are condition and he wants us to trust in him.
Psa 121:5 The LORD is thy keeper: the LORD is thy shade upon thy right hand.
Psa 121:6 The sun shall not smite thee by day, nor the moon by night.
In the physical it is very hot and in the spiritual a hot war is being waged against righteousness. Our Lord is our righteousness.
Psa 121:7 The LORD shall preserve thee from all evil: he shall preserve thy soul.
Lead us not into temptation and keep us from evil my LORD and my comforter.