It is known that khechari mudra is related to higher yogic practice.
But is there a hand mudra called khechari as well apart with the actual mudra?
Yes there is.
In The Nitya ShodAshika Arnava Tantram (NSA), Lord Shiva depicts how to form the Khechari Mudra using the hands.
The 3rd Patala of the text is entirely dedicated to describing the Mudras that are used during the worship of Goddess LalitA MahAtripura Sundari.
The 1st verse itself is this:
Sri Devi UvAcha- BhagavanstripurAmudrAh suchitA na prakashitAh |
Katham virachanam tasAm kriyate vada shankara ||
Where Mother Goddess is saying - "O Bhagavan, you have , till now, only indicated about the Tripura Mudras but have not revealed them. Now, please describe how to form these MudrAs O Shankara."
Lord Shiva then gradually describes how to form some of the famous Mudras like - Trikhanda, SarvasamkshovakArini, TrailokyAkarshanakArini etc..etc...
Khechari- the Hasta MudrA, is then described in the following verses:
Savyam dakshina deshe tu dakshinam savyadeshatah |
BAhum kritvA maheshAni hastau samparivartya cha ||
KanishthAnAmike devi yuktA tena kramena tu |
TarjanibyAm samAkryante sarvodhvamapi madhyame ||
Angushthou tu maheshAni kArayet saralAvapi |
Iyam sA khechari nAma mudrA sarvottama priye ||
The left arm should be in the right direction and the right arm in the left; then the right arm should be placed encircling the left hand and the fingers should be made to intertwined; Now, alternatively the little fingers to be intertwined with the two ring fingers; the middle fingers should be looking up and on their side the index fingers are to be placed; and O Consort of Mahesha, by the help of the middle and other fingers, the thumbs should be made to stand erect in a line. O beloved, in this manner is formed the best of all MudrAs called the Khechari.
Further verses, given below, describe what's the significance of the Mudra is and what are few things that are achieved on it's mastery.
Rachiteyam mahAdevi sarvatejopahArini |
BandhayivaitayA devi drishyate sAdhakottamah ||
Yogini sarvavrindeistu jvalat pAvaka sannibhah |
DAkini rAkini vrindair lAkinikAkini ganaih ||
SAkini hAkinibhistu dhyAteyam parameswari |
EtayA gyAtayA devi yogininAm bhavet priyah ||
Yatah samayamudreyam sarvAsAm parikirtitA ||
O Great Goddess, one who forms this MudrA steals all others' Tejas, by doing so. By forming this MudrA, the aspirant looks like a burning flame of fire, along with all the Yoginis. O Supreme Goddess, the Saktis- DAkini, RAkini, LAkini, KAkini, SAkini, HAkini- always meditate upon this MudrA. This MudrA is also called the "Samaya MudrA" of all the Saktis, and hence, the aspirant who has it's knowledge, becomes very dear to the Yoginis.
On these verses, one of the 3 commentators, Sri SivAnanda, interpret "Yogini" to mean -- BrAhmi... MahAlakshmi and other such Saktis.
And, another verse, which says, that by performing this Mudra one also achieves the power of flying (a Siddhi that the "original" Khechari is also supposed to bestow)
Prajatoha prajato vAhapi shuchau deshehathavAha shuchau ||
Utthito vopavishtastu chakramannishchalohapi vA |
Ucchisto vA shucirbhutvA bhugyAno maithune ratah ||
MudrAyA madhyamAngulyou parivartya kramena tu |
PArthive sthAnake yuktvA sadyah khecharatAm vrajeth ||
Whether the aspirant (who forms the MudrA) is pure or impure, whether the place is pure or impure, whether he is on the move or static, whether he has washed himself after eating or not etc--- in all such circumstances, if he, upon performing the Khechari MudrA, places the middle fingers on the place called "PArthiva" he immediately attains Khecharatva (i.e gets the power of flying).
Sri BhAskara RAya's commentary on the "PArthiva SthAna" is as follows:
PArthiva SthAna- "PArthiva sthAnam nAma murdhAstitahmahAbindusthAnamityAhuh" --- The place of the the MahAbindu, that is situated in the palate (MurdhA) is called the " PArthiva SthAna".
And for the word "KhecharatAm" he says:
Khe bodha gagane charatiti khecharah | Khecharasya bhAvah khecharAta||
Khe--- Bodha Gagane or the space or sky of consciousness; one who travels in that is Khechara. And the BhAva (state) of Khechara is KhecharatA or the power of traveling in the space-consciousness..
So, as per him it's not literal but symbolic.