YV 2.7h

Pain afflicts the breaths of the people if rain does not fall, the cups are breaths; verily he frees the breaths of the people from pain, and rain soon falls. (The cup) for Indra and Vayu is connected with the Gayatri, the opening day is connected with the Gayatri, and therefore on the opening day (the cup) for Indra and Vayu is drawn; verily he draws it in its own abode. The Çukra is connected with the Tristubh, the second day is connected with the Tristubh, and therefore on the second day the Çukra is drawn; verily he draws it in its own abode. The Agrayana is connected with the Jagati, the third day is connected with the Jagati, and therefore on the third day the Agrayana is drawn; verily he draws it in its own abode. In that it completes the metres, it completes the sacrifice [1]; in that the Agrayana is drawn on the next day, where they have seen the sacrifice, thence does he again employ it. The second three nights begin with the Jagati, the Agrayana is connected with the Jagati; in that the Agrayana is drawn on the fourth day, he draws it in its own abode; verily also they revolve round their own metre. (The cup) for Indra and Vayu is connected with the Rathantara (Saman), the fifth day is connected with the Rathantara, and therefore on the fifth day [2] (the cup) for Indra and Vayu is drawn; verily he draws it in its own abode. The Çukra is connected with the Brhati, the sixth day is connected with the Brhati, and therefore on the sixth day the Çukra is drawn; verily he draws it in its own abode. In that it completes the metres, it completes for the second time the sacrifice; in that the Çukra is drawn on the next day, where they have seen the sacrifice, thence does he again employ it. The third three nights begin with the Tristubh, the Çukra is connected with the Tristubh [3]; in that the Çukra is drawn on its seventh day, he draws it in its own abode, and they revolve round their own metre.