John Wesley on Numbers 5:18

Before the Lord - Before the tabernacle with her face towards the ark. Uncover her head - Partly that she might be made sensible how manifest she and all her ways were to God; partly in token of her sorrow for her sin, or at least for any cause of suspicion which she had given. In her hands - That she herself might offer it, and thereby call God to be witness of her innocency. Bitter - So called either from the bitter taste which the dust gave it, or from the bitter effects of it upon her, if she were guilty. That causeth the curse - Not by any natural power, but by a supernatural efficacy.