The 105th prohibition is that we are forbidden from putting frankincense into the meal offering brought for a sotah (suspected adulteress).
The source of this commandment is G‑d's statement1 (exalted be He), "he shall not place frankincense on it."
The Sifra2 says, "This verse comes to teach you that if one put in either oil or frankincense, he would be transgressing a prohibition. Just as adding oil is a transgression, so too adding frankincense."3 Therefore, even one who transgresses this prohibition receives lashes.4
The Mechilta5 says, "the verse, 'he shall not place oil on it; he shall not place frankincense on it' teaches that these count as two separate punishments."