Personified, often honorific reference to the sun as a divine being or natural force that sees all. Used in expressions like お天道様が見ている (the sun/heaven is watching).
I can't do bad things because the sun (heaven) is watching.
For farmers, the sun is their greatest ally.
天道 (てんとう, 'heavenly way' or 'the sun') + honorific 様 (さま). The reading てんとう for 天道 is a Sino-Japanese reading. The exact historical derivation is uncertain, but the term reflects a traditional view of the sun as a divine, watchful presence.