1 Samuel 20:26

Yet Saul did not say anything that day, for he thought, “It is an incident [of some kind] and he is not [ceremonially] clean—surely he is unclean.”

Leviticus 15:5

Whoever touches his bed shall wash his clothes, and bathe in water, and be unclean until evening;

Leviticus 11:24

‘By [contact with] these you will become unclean; whoever touches their carcasses becomes unclean until the evening (dusk),

Leviticus 11:27

Also all animals that walk on their paws, among all kinds of animals that walk on four legs, are unclean to you; whoever touches their carcasses becomes unclean until the evening,

Leviticus 7:20-21

But the one who eats meat from the sacrifice of peace offerings which belong to the Lord, in his uncleanness, that person shall be cut off from his people [excluding him from the atonement made for them].

Leviticus 11:31

These [creatures] are unclean to you among all that swarm; whoever touches them when they are dead becomes unclean until evening.

Leviticus 11:40

And whoever eats some of its meat shall wash his clothes, and be unclean until evening; also whoever picks up its carcass shall wash his clothes, and be unclean until the evening.

Leviticus 15:16-17

‘Now if any man has a seminal emission, he shall wash all his body in water, and be unclean until evening.

Leviticus 15:19-21

‘When a woman has a discharge, if her bodily discharge is blood, she shall continue in her menstrual impurity for seven days; and whoever touches her shall be unclean until evening.

Numbers 19:16

Also, anyone in the open field who touches one who has been killed with a sword or who has died [of natural causes], or a human bone or a grave, shall be unclean for seven days.

1 Samuel 16:5

And he said, “In peace; I have come to sacrifice to the Lord. Consecrate yourselves and come with me to the sacrifice.” He also consecrated Jesse and his sons and invited them to the sacrifice.

Treasury of Scripture Knowledge

Summary

Nevertheless Saul spake not any thing that day: for he thought, Something hath befallen him, he is not clean; surely he is not clean.

Bible References

He is not clean

Leviticus 7:21
When anyone touches any unclean thing—human uncleanness, or an unclean animal, or any unclean detestable thing—and then eats the meat of the sacrifice of the Lord’s peace offerings, that person shall be cut off from his people [excluding him from the atonement made for them].’”
Leviticus 11:24
‘By [contact with] these you will become unclean; whoever touches their carcasses becomes unclean until the evening (dusk),
Leviticus 15:5
Whoever touches his bed shall wash his clothes, and bathe in water, and be unclean until evening;
Numbers 19:16
Also, anyone in the open field who touches one who has been killed with a sword or who has died [of natural causes], or a human bone or a grave, shall be unclean for seven days.