Symbols - What does heaven look like
The swallow takes on the symbolism of all birds.
In all shamanic societies it represented an extremely special shaman - one with a gift of extremely competent out of body manoevering and one capable of travelling very long distances out of body. Thus a swallow person was greatly revered. The forked tail was associated with thunder and lightning and the fact it appeared in the Spring made it a bird representative of the last stages on the spiritual path - see the Four seasons and the hours, in effect a shaman or spiritual traveller on the red route and very close to achieving annihilation and becoming a god.
And there is more, if we look at the actual bird itself we see another characteristic borrowed symbolically.
The swallows and martins are a group of passerine birds, characterised by their adaptation to aerial feeding. …Swallows have adapted to hunting insects on the wing by developing a slender streamlined body and long pointed wings, which allow great maneuverability and endurance, as well as frequent periods of gliding. Their body shape allows for very efficient flight, which costs 50-75% less for swallows than equivalent passerines of the same size. Swallows usually forage at around 30–40 km/h, although they are capable of reaching speeds of between 50–65 km/h when traveling
Insects are universally symbolically the spirit beings of chemicals such as drugs and some of them [as will be seen from the observations for insects] are not at all pleasant. The pharmaceuticals invented by man have produced some truly evil looking spirit beings in the form of insect like creatures within dreams, visions and hallucinations.
Swallows eat insects, it is one of their principle skills, the ability to fly acrobatically and catch insects in the air. In effect a swallow is a destroyer of evil beings. And
Pairs of mated swallows are monogamous. Overall the contribution of male swallows towards parental care is the highest of any passerine bird.
A Dictionary of Symbols – J E Cirlot
A bird sacred to Isis and to Venus and an allegory of spring. The poet Becquer makes use of this symbol to convey the pathos and the inexorable nature of time, drawing analogies with other symbols