image credit:
https://www.moleiro.com/vista/estaticos/formateadas/SS_5c0503af511af_hombrees2_6.jpg
The border on Plate 3 again has plants and animals. Plants are again represented with buds, blooms, and fruit. The owl and the peacock remain, though a peahen (center left) has joined the menagerie.
The knight, wearing a crowned helm reminiscent of the helmet of the coat of arms on Plate 1, straddles a double-fountain, holding a red shield and a sword. Around his helmet are seven stars of different metals, representing the alchemical metals of lead, tin, iron, quicksilver, copper, silver and gold. His breastplate displays the colors of the transmutations of alchemy—Nigredo, Albedo, Citrinitas, and Rubedo. (And after Rubedo, another phase of Nigredo shows.) The knight is a Unity of Air (the sword) and Fire (the red shield).
His shield contains the text Ex duabus acquis / unã facite Qui / quæritis Sole et Lu / nã facere. et date / bibere inimico urõ / Et uidebitis / eum mortuum / Deiñ de aqua ter / rã facite. Et Lapi / de multi / plicas / tis, “From two waters, make one, all those who seek to create sun [gold] and moon [silver]. Give it to your most fervent enemy to drink. And you will see his corpse. Then make earth from water and multiply the stone.” (translation from https://www.moleiro.com/en/miscellanea/splendor-solis/miniatura/1629).
The double fountains contain gold and silver, the first separation of the prima materia. Though they are separated, they are still united. They are a Unity and a Duality, Chokmah.