Devibhagavatapurana 5.33.26

5.33.26

sphuradoṣṭhau vepamānau lohitākṣau babhūvatuḥ |
prādurbabhūva sahasā tayorvivadamānayoḥ ||

The Risi said:-- Thus engaged in disputing with each other, their lips were quivering with anger and their eyes got red. When, Behold! there appeared suddenly between those two disputants, a nectar-like white phallic emblem (Lingam), wonderfully long and extensive. Then a voice, from without anybody, broke out in the Heavens and addressed Brahmâ and Visnu who were quarrelling thus! Whoever amongst you will be able to go to the other end of this Lingam whether beyond its top or below its bottom, he is certainly the superior of you two; let one of you therefore go down to Pâtâla and let the other go up to the Heavens. Leave off your useless disputations and take my word as proof. It is always advisable to select an umpire to decide such a quarrel as this that has sprung up between you two.