Hebrews 4:15

For we have not an high priest
That is cruel and unmerciful; the saints have an high priest, but not such an one:

which cannot be touched with the feeling of our infirmities;
such as bodily diseases and wants, persecutions from men, and the temptations of Satan; under all which Christ sympathizes with his people; and which sympathy of his arises from his knowledge and experience of these things, and the share he has had of them, and from that union there is between him and his people: and it is not a bare sympathy, but is attended with his assistance, support, and deliverance; and the consideration of it is of great comfort to the saints:

but was in all points tempted like as we are:
of the temptations of Christ, and of the saints, (See Gill on Hebrews 2:18)

yet without sin;
there was no sin in his nature; though he was encompassed about with infirmities, yet not with sinful infirmities, only sinless ones; nor was there any sin in his temptations; though he was solicited to sin by Satan, yet he could find none in him to work upon; nor could he draw him into the commission of any sin.