Mercury square Lilith (orb 3.6°) creates concrete friction between the two planets. The orb is moderate; it stays secondary beside tighter signatures.
Here, Mercury in Virgo in House 6 brings intellect, language, thought, and technique into House 6 (daily work, technique, and bodily discipline), with Virgo style (precision, method, usefulness, and attention to detail); Lilith in Sagittarius in House 9 brings pure ideal, absolute demand, fascination, and refusal of compromise into House 9 (vision, belief, study, and wider horizons), with Sagittarius style (expansion, travel, belief, and the search for meaning).
Concrete friction: this aspect creates tension between thought, speech, obsession, purity demand, and refusal to let go. Visible angle: Mercury near the Descendant (orb 3.6°) touches an angle; this aspect is easier to notice through direct relationships, partners, opponents, and the way others are met. House 6 (daily work, technique, and bodily discipline) is in friction with House 9 (vision, belief, study, and wider horizons); this can create blockage, inhibition, overreaction, or repeated conflict between the two fields.