A FAQ on the Azzam Publications website explained that "In the Hearts of Green Birds" refers to what is inside.
1	A	a	DET	DT	Definite=Ind|PronType=Art	2	det	2:det	_
2	FAQ	faq	NOUN	NN	Number=Sing	8	nsubj	8:nsubj	_
3	on	on	ADP	IN	_	7	case	7:case	_
4	the	the	DET	DT	Definite=Def|PronType=Art	7	det	7:det	_
5	Azzam	Azzam	PROPN	NNP	Number=Sing	6	compound	6:compound	_
6	Publications	Publication	PROPN	NNPS	Number=Plur	7	compound	7:compound	_
7	website	website	NOUN	NN	Number=Sing	2	nmod	2:nmod:on	_
8	explained	explain	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	0:root	_
9	that	that	SCONJ	IN	_	18	mark	18:mark	_
10	"	"	PUNCT	``	_	13	punct	13:punct	SpaceAfter=No
11	In	in	ADP	IN	_	13	case	13:case	_
12	the	the	DET	DT	Definite=Def|PronType=Art	13	det	13:det	_
13	Hearts	heart	NOUN	NNS	Number=Plur	18	obl	18:obl:in	_
14	of	of	ADP	IN	_	16	case	16:case	_
15	Green	green	ADJ	JJ	Degree=Pos	16	amod	16:amod	_
16	Birds	bird	NOUN	NNS	Number=Plur	13	nmod	13:nmod:of	SpaceAfter=No
17	"	"	PUNCT	''	_	13	punct	13:punct	_
18	refers	refer	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	8	ccomp	8:ccomp	_
19	to	to	SCONJ	IN	_	20	case	20:case	_
20	what	what	PRON	WP	PronType=Int	18	obl	18:obl:to	_
21	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	22	cop	22:cop	_
22	inside	inside	ADV	RB	_	20	acl:relcl	20:acl:relcl	SpaceAfter=No
23	.	.	PUNCT	.	_	8	punct	8:punct	_
