Kamasutra 3.5.28

3.5.28

pūrvaḥ pūrvaḥ pradhānaṃ syād vivāho dharmataḥ sthiteḥ/
pūrvābhāve tataḥ kāryo yo ya uttara uttaraḥ//

There are verses on this subject as follows:—In all the forms of marriage given in this chapter of this work, the one that precedes is better than the one that follows it on account of its being more in accordance with the commands of religion, and therefore it is only when it is impossible to carry the former into practice that the latter should be resorted to. As the fruit of all good marriages is love, the Gandharva form of marriage is respected, even though it is formed under unfavorable circumstances, because it fulfills the object sought for. Another cause of the respect accorded to the Gandharva form of marriage is, that it brings forth happiness, causes less trouble in its performance than the other forms of marriage, and is above all the result of previous love.