פירוש על קידושין 108:4

R. Nahman rules in accordance with tannaim that agree with anonymous views in tannaitic literature. Thus, like R. Meir, second tithe is considered sacred and betrothal with it is not valid.
But the halakhah follows R. Judah in respect to hekdesh. If unwittingly, he has betrothed her. If intentionally, he has not.