We have the Words by 'Abdu'l-Baha in Paris Talks regarding the Light in meditation.

We also have Baha'u'llah speaking of the Cave. In this can be found another means (technique) for advancing ones own method of meditation.

Imagine being several yards (meters) inside a cave looking out. The perimeter of the opening is apparent. Step towards this light, then step out of the Cave and into the Light.

Your journey has begun. Be observant. Be attentive.

The Cave is made reference in the 3rd Valley of the Treatise by Baha'u'llah as is known as The Four Valleys. It is easily expounded upon as one would view the Cave of Elijah and others of renown. Baha'u'llah makes mention of Surah 18:16 as some have interpreted the Chapter as The Cave in the Quran.

In meditations among Christian mystics, the wayfarer places his own being on the Tree, as is also the Cross. Meditating, as concerns the Cave, likewise we may place our own being within it. Herein, the Cave becomes a metaphor as regards our own silent inner sanctum.