Taittiriya Upanishad 3.10.1

3.10.1

na kañcana vasatau pratyācakṣīta /
tadavratam /
tasmādyayā kayā ca vidhayā bahvannaṃ prāpnuyāt /
arādhyasmā annamityācakṣate /
etadvai mukhato 'nam̐ rāddham /
mukhato 'smā annam̐ rādhyate /
etadvai madhyato 'nam̐ rāddham /
madhyato 'smā annam̐ rādhyate /
edadvai antato 'nnam̐ rāddham /
antato 'smā annam̐ rādhyate // 1//

His vow is that he should not refuse anyone come for shelter. Therefore one should collect plenty of food by whatsoever means he may. (And one should collect food for the further reason that) they say, "Food is ready for him". Because he offers cooked food in his early age with honour, food falls to his share in the early age with honour. Because he offers food in his middle age with medium courtesy, food falls to his share in his middle age with medium honour. Because he offers food in this old age with scant esteem, food falls to his share in old age with scant consideration. To him who knows thus (comes the result as described).

(Brahman is to be meditated on) as preservation in speech; as acquisition and preservation in exhaling and inhaling; as action in the hands; as movement in the feet; as discharge in the anus. These are meditations on the human plane.

Then follow the divine ones. (Brahman is to be meditated on) as contentment in rain; as energy in lightning.