# Ahithophel saw

"Ahithophel knew" or "Ahithophel realized"

# his advice had not been followed

"Absalom had not followed his advice"

# saddled his donkey

placed a blanket or small leather seat on the donkey so he could sit on it

# set his house in order

"prepared for his death" 

# So

"And this is how"

# was buried

"they buried him"