The third house is the house of siblings and communications. In traditional astrology, the third house was known as the house of the Moon goddess because it was about bringing the sacred close to home. Most goddesses ruled the local environment so you had dedicated goddesses for lakes, rainbows, bread, trees etc. Local shrines were dedicated to these Goddesses. The moon is in its joy here and its co-significator is the zodiac sign of Gemini
“ Hath signification of brethren, sisters, cousins or kindred, neighbours, small journeys, or inland-journeys, oft removing from one place to another, epistles, letters, rumours, messengers: It doth rule the shoulders, arms, hands and fingers.
Of colours, it governeth the red and yellow….It is a cadent house, and is the joy of the Moon; for if she be posited therein, especially in a moveable sign, it’s an argument of much travel, trotting and trudging, or of being seldom quiet. The house is masculine.””
William Lilly